Electron-vibration coupling constants in positively charged fullerene

Abstract

Recent experiments have shown that C60 can be positively field-doped. In that state, fullerene exhibits a higher resistivity and a higher superconducting temperature than the corresponding negatively doped state. A strong intramolecular hole-phonon coupling, connected with the Jahn-Teller effect of the isolated positive ion, is expected to be important for both properties, but the actual coupling strengths are so far unknown. Based on density functional calculations, we determine the linear couplings of the two a_g, six g_g, and eight h_g vibrational modes to the H_u HOMO level of the C60 molecule. The couplings predict a D_5 distortion, and an H_u vibronic ground state for C60^+. They are also used to generate the dimensionless coupling constant <lambda> which controls the superconductivity and the phonon contribution to the electrical resistivity in the crystalline phase. We find that <lambda> is 1.4 times larger in positively-charged C60 than in the negatively-doped case. These results are discussed in the context of the available transport data and superconducting temperatures. The role of higher orbital degeneracy in superconductivity is also addressed.

22 pages - 3 figures. This revision includes few punctuation corrections from proofreading

Cited by in corpus (16)

• Strongly Correlated Superconductivity
• Electron-phonon coupling in the C60 fullerene within the many-body GW approach
• Dynamic Jahn-Teller effect in electron transport through single C60 molecules
• Exotic s-wave superconductivity in alkali-doped fullerides
• Vibronic coupling in C${}_{60}^{-}$ anion revisited: Precise derivations from photoelectron spectra and DFT calculations
• Jahn-Teller Spectral Fingerprint in Molecular Photoemission: C60
• Coulomb couplings in positively charged fullerene
• Hund's rule Magnetism in C60 ions?
• Dynamical Jahn-Teller effect of fullerene anions
• Multiplet Structures of Charged Fullerenes
• Quadratic Jahn-Teller effect of fullerene anions
• Comment to "Experimental Evidence of a Dynamic Jahn-Teller Effect in C60+"
• Jahn-Teller distortions and excitation energies in C60(n+)
• Dynamical Jahn-Teller effect in the first excited C${}_{60}^{-}$
• Low-energy excitations of a linearly Jahn-Teller coupled orbital quintet
• First principles study of the vibronic coupling in positively charged C${}_{60}^{+}$